This invention relates to a device intended for use as a pocket or portable unit for the use in oral inhalation therapy and to a process for using the device.
Currently, available devices for oral inhalation therapy employ halogenated hydrocarbons such as dichlorodifluoromethane as a propellent. Such propellents, for example, Freon.RTM., a registered trademark, are under scrutiny by various agencies of the federal government because of possible deleterious effects on the human body and on the environment. The dispenser of the present invention excludes the administration of halogenated hydrocarbons from the lung and from the environment during use.
U.S. Pat. No. 3,219,533 discloses many solid medicaments, including such steroids as hydrocortisone, prednisolone and dexamethasone dispersed in the particle size range of 0.5 to 10 microns in certain chlorofluoro alkanes using 0.5 to 5.0% ethanol, for inhalation and opthalmic therapy. U.S. Pat. No. 3,888,253 discloses a device for the administration of solid medicaments which uses the intake of breath as the means of power. Other patents, for example, U.S. Pat. No. 3,831,606 discloses means for atomizing the medicament. The present invention is an improvement over the device shown in U.S. Pat. No 3,831,606. Because the medicament capsule of the present invention is opened before being placed in the dispenser, more powder can be available for inhalation. That is, as contrasted to shattering in the dispenser, there is the possibility of complete use of all the powder from the medicament capsule by the use opening the capsule before inserting into the dispenser. Further, the atomizing means and the blower are combined into one impeller. There should thus be less powder loss because of the reduced surface area. Still further, the power source of the present invention is separated from the powder dispenser housing by a baffle or by a separate housing. Finally, the power source of the present invention may, but does not have to be, a battery driven motor. Still, other patents e.g., U.S. Pat. No. 3,948,264 discloses devices which use a vibration means and an intake of breath to administer a solid medicament. The patents discussed above are incorporated herein by reference.
What has been lacking in the prior art is a dispenser which will accurately dispense a certain amount of medicament, at a given velocity, and a given particle size. The nonhalogenated hydrocarbon devices heretofore have not in general provided this.
The discovery has now been made that an impeller contained in a housing which is attached to a converging funnel-shaped mouthpiece provides an accurate degree of atomization for medicament powders of different weight, powder density, and particle size. The type of impeller and the convergence of the funnel-shaped mouthpiece can be changed to accommodate medicament powders with different weight, powder density, and particle size. The advantages of the impeller in accurately atomizing and blowing the medicated powder into the mouthpiece lies in the fact that the impeller slings the powder in an arked path by centrifugal force out of the circular housing. The impeller thus provides a most accurate method of administering a prescribed dosage of medicated powder into the mouth and bronchial tree by inhalation.
In the event the federal government bans the use of halogenated hydrocarbon propellant devices, this dispenser can be a replacement as a accurate metered dose can be delivered without Freon.RTM. or other halogenated hydrocarbons.
Because the power source of the oral inhalator powder dispenser does not need to be propelled by a halogenated hydrocarbon gas, the potential environmental pollution of the ozone layer of the earth can be minimized by the use of this dispenser. Of equal importance is the fact that this dispenser utilizes air as the medium for aerating the powder medicament. Therefore, the inhalator does not subject the user to any foreign gaseous substance with the use of this dispenser.